Hazardous Substances

What are hazardous substances and how do they impact a real estate transaction?

There are many different kinds of hazardous substances.  Some are natural, such as radon, and some are human-made, such as lead paint.  Hazardous SubstancesGenerally, overexposure to any hazardous substance will cause health problems for those exposed.  It is critical to determine any hazardous materials are present when selling or buying a property.

Can you elaborate more on the different kinds of hazardous substances that could impact a real estate transaction?

Sure.  Below you will find a list of hazardous substances with their unique characteristics:


Asbestos was banned in 1978, so if you are selling or buying a home built after that, you are good.  However, if you are buying or selling a home built before 1978, chances are it may have been constructed using asbestos.  The problem with asbestos is it becomes friable, which means it breaks down into little particles.  If asbestos particles are inhaled, they can cause respiratory issues, such as lung cancer.  So, how do you deal with asbestos?  Well, you can remove it, let it be, or cover it up, which is known as encapsulation.


It turns out 1978 was a good year for health in the construction industry.  In 1978 they also decided to ban the use of lead in paint.  Before 1978, lead had been used in paint.  Anyone exposed to that lead paint could get sick, especially if any flakes were inhaled or ingested.  In 1992 a federal law called the Residential Lead-Based Paint Hazard Reduction Act was passed.  This law requires any licensees involved in the lease, sale, management, renovation, or appraisal of property built before 1978 follow specific guidelines related to notification of the possibility of the presence of lead paint.


Mold has been a big one recently.  There are mold spores everywhere in the air.  It’s when they land on a moist organic substance that mold can grow.  So, if there is a water leak that lingers for some time in an enclosed space, there is a chance that mold can grow.  The higher the chance materials that are moistened by a leak remain damp, such as in high humidity locations, the higher the chance mold will form.  Of course, exposure to toxic mold can have a negative impact on one’s health.  Black mold is a form of mold that is highly toxic.


Radon is an odorless, colorless radioactive gas which is produced by the natural decay of radioactive substances.  It can enter a property through cracks in the foundation.  There are tests that can be done to determine whether or not radon is present in a property, and how profoundly it is concentrated.

Is this a complete list of all the hazardous substances which may be present?

No, it is not. However, it is an excellent list of those that you need to know for your real estate licensing exam.

What else can help me prepare to pass my real estate licensing exam on my first attempt?

Other tips to help you pass your real estate licensing exam on your first attempt:

Real Estate Test Taking Tips

How to Pass the Real Estate Exam

Real Estate Exam Math Made Easy

Also, check out our question of the day videos on our YouTube channel:

PassMasters Real Estate Exam Prep YouTube Channel